Rebased WIP: Infrastructure: sceNetInet and sceNetResolver support

[hrydgard]

This is #18578 by @JustAWhiteBloodCell, but rebased on the latest codebase.

No clue if it works, but figure it might be a good idea to get it in, as the way it currently is, nobody can work on it. See the other issue for more reasoning about which infrastructure PR to merge.

[Linblow]

The way I see it the whole network infrastructure code should be done using the (standalone) Asio C++ library as the network backend. It's robust, well known, and supports lots of platforms, so we wouldn't need to write platform-dependent code. It's also worth noting the current C++ networking technical specification is based on the Asio C++ networking library.

[hrydgard]

That might indeed be a good idea. However I'm not very good at networking and I've never used asio, so switching over isn't gonna be the first priority.

But, none of the changes I'm planning to make is likely to make it harder to switch either.

[lesleyrs]

This is #18578 by @JustAWhiteBloodCell, but rebased on the latest codebase.

No clue if it works, but figure it might be a good idea to get it in, as the way it currently is, nobody can work on it. See the other issue for more reasoning about which infrastructure PR to merge.

Just FYI: yes it seems to work! I was able to get my C port of runescape 2 (mmorpg) working on psp thanks to this, where the latest release was giving unimpl errors!

https://github.com/lesleyrs/Client3/tree/main/docs - there will be psp image here later